[NBLUG/talk] Curious Clock Drift

[Robert Hayes]

I'm running Debian installed from a Knoppix 3.2 dist on a 4 month old Dell 
(don't tell me that's the problem...)

My root cron file includes:

rdate -s time.nist.gov
hwclock --systohc

to run daily.

A week or so ago I noticed the clock was about 8 minutes behind the one 
embedded in my coffee mug.

I ran rdate manually, and all was well.

Same thing yesterday.

TODAY, the computer is 20 MINUTES slow. 

Any ideas? The onboard MB battery should just die, right, not result in a slow 
clock? And besides, could it lose 20 minutes in 24 hours?